1. Field of the Invention
The present invention relates to a sheet original conveying apparatus and an image forming apparatus having such a sheet original conveying apparatus. More particularly, it relates to a sheet original conveying apparatus effective to feed, for example, a continuous sheet including folds therein, such as a computer form (referred to as "CF sheet" hereinafter), as an original to be read. However, the original is not limited to such a continuous sheet; the sheet original conveying apparatus can be applied to successively convey short cut sheet originals.
2. Related Background Art
In the past, various sheet original conveying apparatuses for handling a continuous sheet such as a CF sheet as an original have been developed and put to practical use. In such apparatuses, generally, the reading of an original and the image formation were performed at a constant speed from beginning to end.
However, in such conventional apparatuses, and particularly in the case of a high speed system, since the reading of the original and the ejection of copy sheets were performed at a high speed, if the image density of the original was extremely thin, thereby generating a poor copy, or if the setting of the copy density was improper, thereby generating a poor copy, then it was feared that a large number of erroneous copies would generated before an operator became aware of the existence of the poor copy.
On the other hand, particularly in a case where a CF sheet was used as an original, when the CF sheet was conveyed at a high speed, since the CF sheet was continuously sent to an ejection tray in succession, before the read CF sheet could be correctly folded on the ejection tray, it was feared that the CF sheet might be damaged.